Fuel cell stack

Abstract

A first membrane electrode assembly is interposed between a first separator and a second separator. A second membrane electrode assembly is interposed between the second separator and another first separator. The second separator includes a first separator plate, a second separator plate, and a leaf spring interposed between the first separator plate and the second separator plate. Each of the first separator plate and the second separator plate has an embossed section made up of first protrusions protruding toward the leaf spring and first recesses spaced from the leaf spring. The first protrusions of the embossed section in one separator plate are in alignment with the first recesses of the embossed section in the other separator plate, respectively.

1. A fuel cell stack comprising a stacking body formed by stacking a plurality of assemblies each interposed between separators, each of said assemblies including an anode, a cathode, and an electrolyte interposed between said anode and said cathode, said stacking body being tightened by a pair of end plates provided at opposite ends of said stacking body in the stacking direction,
 wherein at least one of said separators includes a pair of separator plates and a metal plate interposed between said separator plates; 
 each of said separator plates has an embossed section comprising protrusions protruding toward said metal plate and recesses spaced from said metal plate; and 
 said protrusions of said embossed section in one separator plate face said recesses of said embossed section in the other separator plate, respectively, 
 wherein a coolant flow passage is formed between said metal plate and one separator plate, and between said metal plate and the other separator plate. 
 
   
   
     2. A fuel cell stack according to  claim 1 , wherein each of said separator plates has a straight groove section comprising protrusions protruding toward said metal plate and grooves spaced from said metal plate; and
 said protrusions of said straight groove section in one separator plate are in alignment with said grooves of said straight groove section in the other separator plate, respectively. 
 
   
   
     3. A fuel cell stack according to  claim 2 , wherein a straight reactant gas flow passage is formed between said membrane electrode assembly and said pair of separator plates, and a reactant gas flows through said straight reactant gas flow passage along said straight groove section. 
   
   
     4. A fuel cell stack according to  claim 2 , wherein a serpentine reactant gas flow passage is formed between said membrane electrode assembly and said pair of separator plates, and a reactant gas flows through said serpentine reactant gas flow passage along said straight groove section. 
   
   
     5. A fuel cell stack according to  claim 1 , wherein said metal plate is a leaf spring. 
   
   
     6. A fuel cell stack according to  claim 1 , further comprising a pair of brackets attached to said pair of end plates, said pair of brackets being secured to a vehicle body for mounting said fuel cell stack on said vehicle body.